Compressor system



May 2n w24. 1,494,957'

F. D. HOLDSWORTH COMPRESSOR SYSTEM Filed Feb. 17, 1923 (l f5 A zj a v l Z8 4 l? l ZY' 4 Patented May 20, 1924.

UNITED STATES FRED D. HOLDSWOBTH, OF CLABEMONT,

'PATENT HAMPSHIRE, ASSIGNOBTO SULLIVAN MACHINERY COMPANY, A comonn'noN or MASSACHUSETTS.

COMPRESSOR SYSTEM.

Application led February 1'?, 1923. Serial No. 319,614.

To all whom z't may concern.'

Be it known that I, FRED D. HoLDswoR'rH, a citizen of the United States, residing at Claremont, in the county of Sullivan and 5 State of` New Hampshire, have invented certain ynew and useful Improvements in Compressor Systems, of which thefollowing is a full, clear, and exact specification.

My invention relates to compressor systems,

of the automatically controlled type.

An object of my invention is to rovide an -improved compressor system. nother object of my invention is to provide an improved compressor drive controlling mechanism. A further object of my invention is to provide an improved compressor system comprising a motor driven compressor and means of improved nature for controlling the driving of the compressor by the motor. A still further object of my invention is to provide 'an improved compressor system comprisin a compressor, a synchronous motor operatln Athe same, and improved controlling mec anism responsive to receiver pressure for controlling the o eration of the synchronous motor. Other o jects and advanta es of my invention will hereinafter more ully appear.

In the accompanyin drawings I have shown for purposes of ilustration, one form which my lnvention may assume in practice.

In these drawings,

Fi 1 is a side elevation with details omitted o the illustrative embodiment of my invention.

Fig. 2 is a view, artiallyin elevation andl partially in centra vertical section,'through a portion of the controlling mechanism.

It is a well-known fact that a synchronous motor drive is quite desirable for use in connection with air compressors. Heretofore in the employment of such a drive it has, however, been found requisite to causel the compressor driving motor to run con- 'tinuously and to unload the compressor when further air was not desired for a short period, this in view of the starting characteristics of such motors. According to my invention it is possible, although still employing a synchronous motor, to use the system of compressor control wherein compressor drive is interrupted when for a period no further air need be compr although it will be understood that where very frequent and more particularly to such systems v mature is herein journaled for rotation in vbearin s concentric with the bearings for the field, a though it will be understood that it may be journaled simply upon the shaft 4 or otherwise as preferred. As a result thearmature is free to rotate and as rotation of the field is impeded by the necessity of doing work in turning over the compressor, upon supply of current to the motor, the armature will come up to synchronous speed while the field remains stationary. For the urpose of braking the armature and therey causing the field to rotate, there is provided a brake band 6 surrounding the armature. The details of the motor require no further disclosure since such motors havin both field and armature rotatably supporte together with braking means for the armature are .per se old. For the purpose of controlling the brake band I providemechanism which comprises a lever 8 which, when its free end is moved,l downwardly, applies the brake band 6, and operating means -for the 10 a piston 11 having' a piston rod 12 is reclprocable, the piston rod 12 being connected by a slot and pin connection 13 with the lever 8. For the purpose of governing the reciprocation of the piston 11 and so the applying and releasing of the brake band 6,

have shown a compressor discharge pressure controlled valve mechanism. A receiver 14 receives air through the pi e 15 from the compressor and a line 16 lea s from the receiver and conducts receiver pressure to the controlling valve mechanism which is enerally designated 17. The line 16 is erein shown as branched, one branch leading to a pilot valve 18 of the so-called Judson type. This pilot valve is now so well-known that no detailed description thereof is believed necessary, it being Sumcient to state that when receiver pressure rises above the limit for which the valve is set vthe valve opens.,

and sup lies receiver ressure to themecha- 'nism w ich it contro s, while when the receiver pressure falls below a desired limit the supply through the valve is interrupted and the air previously supplied is permitted to escape through a suitable vent. Herein the pilot valve 18 supplies pressure through a rt 19, to a casing 20 Ain whose bore 21 a t ree-spool piston valve 22 isreciprocable. The casing 20 receives about midway of its length a supply of air Athrough a connection 23 which is herein shown as connected to the other branch of the pipe16, but which in practice might perhaps better be lead directly to the receiver so that the pilot valve mightl not be vsubjected to fluctuations resulting from assage of air to the cylinder 9. Spaced ex aust ports 24 and 25 are arranged respectively above and below the communication of the passage 23 with the casing 20. At the opposite side of the casing 20 there are arranged connections 26 and 27 leading respective y to the bottom and top of the cylinder 9. A spring 28 is arranged below the piston valve 22 and normal y maintains the same in raised position, the iston 22 when in raised position, operatmg b its lower groove 29 to supply air on top o the piston 11 to apply the brake while its upper groove 30 serves to connect thelower end of the cylinder 9 through the connection 26, with the atmospheric vent 24. In the position shown herein, the pilot valve 18 is open and the piston valve 22 down, and

fluid pressure is passing from the line 23 through the groove 30 and the line 26 to the lower end of the bore 10 and moving the piston 11 upward to release the brake and permit rotation of the armature 5,` while at the same time of course the top end of the bore 10 is vented through the passage 27, groove -29 and port 25, whereupon the field 3 will stop rotating.

The mode of operation of this device will have already been clearly understood, but it may be briefly described as follows: When the compressor is running and owin `to a cessation or reduction in the demand Enr air, receiver pressure goes up above the limit for which the pilot valve 18 is set, the pilot valve will opened by pressure passin through the line 16 and air being sup 'lie to the port 19 will force downwar the piston 22 `to the position shown in Figure 2 and so cause air to besu plied through the .line 23, groove 30 and pipe 26 to act upon thelower surface' of the plston 11 while the upper end of the cylinder bore 10 will be vented through the pipe 27, groove 29 and rt 25. As a result, the brake lever 8 will 'u pushed up, causing the brake to be released and so, since the armature may freely rotate and work must be done in order for ythrottled or a dashpot may Y for purposes lever 8 will be operated to apply the brakev band 6 and so cause the field 3 to take up the drive of theJ compressor 1. In order that ythe brake application may be suitably reguthe line 27 may be be provided if lated andvnot too sudden,

preferred. s

While I have in this application specifically described one form which lmy invention may assume in practice, it will be understood that this form of the same is shown of illustration and that the in-` vention may be modified and embodiedv in other forms without vdeparting from thespirit or the scope of the ap ended claims.

What I claim as new an desire to secure by Letters Patent is:

1. In a ycompressor system, in combination, a compressor, driving means therefor comprising a pluralit of cooperating elements each mounted or rotation and each rotatable on supply of power medium when the other is held stationary, one of said elementsv being connected in driving relation with said compressor, and means controlled by terminal pressure for controlling the rotation of the other of said elements.

2. In a compressor system, in combination, a compressor, driving means therefor comprisin a plurality of elements each mounted` or rotation and each rotatable on supply of ower medium. when the other is held stationary, one of said elements being connected in driving relation with said compressor, land automatic means for braking the other of said elements to interrupt rotation thereof. 3. In a compressor system, in combina tion, a compressor, driving means therefor comprisin a plurality of elements each mounted or rotation and each rotatable on supply of power. medium when the other is h'el stationary, on'e of said elements being connected in driving relation with said compressor, and means controlled b demand for air for braking the other o said elements to interrupt rotation thereof.

4. In a compressor system, in combina-y tion, a compressor, driving' means therefor comprisin a plurality of elements each mounted' or rotation and each rotatable on supply` of p owermedium when the other is held stationary, one of said elements being connected in driving relation with said comressor, and means controlled by compressor y." harge pressure variations for braking lll the other of said elements to interrupt 'rotation thereof.

5. In a compressor system, in combina.- tion, a compressor, driving means therefor comprising a plurality of velements each mounted for rotation and each rotatable on supply of power medium when the other is held stationary, one of said elements being connected in driving relation with said compressor, and means controlled by compressor discharge pressure variations for vbraking the other of said elementsto interrupt rotation thereof, said last4 mentioned means including a servo-motor and a compressor discharge pressure controlled valve mechanism therefor.

6. In a compressor system, in combination, a compressor, driving means therefor comprising a synchronous motor having its rotor and stator both journaled for rotation, means for braking the stator, and means controlled by compressor discharge pressure for applying said braking means. v

. tion,

tion,

7. In a compressor system, in combinaa compressor, driving means therefor comprising a synchronous motor having its rotor and stator both Journaled for rotation, means for braking the stator, and means controlled'by compressor discharge pressure for applying said braking means and including a servo-motorand valve mechanism controlled by compressor discharge pressure.

8. In a compressor system, in combinaa compressor, driving means therefor comprising a synchronous motor having its rotor and stator both journaled for rotation, meansfor braking the stator, and means controlled by compressor discharge pressure for applying said braking means and including al compressor discharge pressure operated servo-motor and valve mechanism controlled by compressor discharge pressure.

In testimony whereof I afx my signature.

FRED D.: HOLDSVVORTH. 

